Koray Hekimoglu
Başkent University
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Publication
Featured researches published by Koray Hekimoglu.
Journal of Digestive Diseases | 2008
Koray Hekimoglu; Yucel Ustundag; Abdurrahim Dusak; Zuhal Erdem; Bulent Karademir; Selim Aydemir; Sadi Gundogdu
OBJECTIVE: Recently developed magnetic resonance (MR) techniques permit fast and correct imaging of the entire biliary tree with a high spatial resolution. The aim of this study was to compare the diagnostic potential of one of these new MR sequences in magnetic resonance cholangiopancreatography (MRCP) procedure and endoscopic retrograde cholangiopancreatography (ERCP) with review of current literatures.
European Journal of Radiology | 2011
Koray Hekimoglu; Yucel Ustundag; Abdurrahim Dusak; Bora Kalaycioglu; Halit Besir; Hüseyin Engin; Oktay Erdem
The aim of this prospective study was to compare the diagnostic role of superparamagnetic iron oxide (SPIO)-enhanced liver magnetic resonance imaging (MRI) versus gadobenate dimeglumine (GbD)-enhanced MRI and computed tomography (CT) investigations for detection of small (less than 1cm) colorectal liver metastases (LMs) of colorectal cancer. Seventy-eight LMs in 16 patients were evaluated with dynamic CT imaging, GbD-enhanced dynamic MR imaging and SPIO-enhanced MR imaging. Two radiologists were reviewed the LMs separately. Agreement between the readers and three algorithms was analyzed. Differences between the lesion detection ratios of the methods were analyzed by two proportion z test. Sensitivity values of each modality were also calculated. Interobserver agreement values with kappa analysis were found to be the best for three modalities and kappa values were 0.866, 0.843, and 1.0 respectively. For all 78 LMs, SPIO-enhanced MRI detected all lesions (100% sensitivity). This sensitivity value was higher than GbD-enhanced MRI, and there was a significant difference (p < 0.05). GbD-enhanced MRI depicted 71 lesions and this modality could not detected 7 lesions (91% sensitivity). This modality had moderate sensitivity, and this value is greater than CT imaging, so there was a significant difference also (p < 0.05). Dynamic triphasic CT imaging detected 64 (R1) and 65 (R2) LMs. This modality had the lowest sensitivity (R1: 0.82, R2: 0.83 respectively). Only SPIO-enhanced MRI was able to detect all LMs less than 1cm. LMs were the best detected with SPIO-enhanced MRI. We recommend SPIO-enhanced MRI to be the primary alternative modality especially for diagnosis of small colorectal LMs.
Diagnostic and interventional radiology | 2009
Koray Hekimoglu; Tanzer Sancak; Meltem Tor; Halit Besir; Bora Kalaycioglu; Sadi Gundogdu
PURPOSE The aim of this prospective study was to evaluate the diagnostic utility of volumetric interpolated breath-hold examination (VIBE) and half-Fourier-acquisition single-shot turbo spin-echo (HASTE) fast magnetic resonance imaging (MRI) sequences in the evaluation of pulmonary progressive massive fibrosis (PMF) in comparison with computed tomography (CT) imaging. If fast MRI is proven to be diagnostically significant, this modality can be used for diagnosis and follow-up studies of PMF patients. MATERIALS AND METHODS Twenty-two PMF lesions from 20 coal workers were evaluated. After CT imaging, patients underwent pre-contrast VIBE, contrast-enhanced VIBE, and HASTE MRI studies for detection and evaluation of the PMF lesions. Measurements of the three groups were evaluated with intra-class coefficients. Correlation levels between sizes, image quality, and artifact were evaluated with linear Pearson correlation analysis. RESULTS There was almost perfect agreement among radiologists for lesion detection with kappa analysis. There was significant agreement between three MRI study groups and gold standard CT images. We found the best agreement values with contrast- enhanced VIBE images for lesion detection and image quality in comparison with CT imaging. Presence of artifact was also lowest with this protocol. CONCLUSION With fast MRI sequences in pulmonary imaging, image quality has significantly improved being very close to that of CT studies. In this study, contrast-enhanced VIBE protocol provided the best depiction of PMF lesions. This protocol may be an alternative choice for CT, avoiding the use of iodinated contrast material and minimizing exposure to ionizing radiation for follow-up studies.PURPOSE The aim of this prospective study was to evaluate the diagnostic utility of volumetric interpolated breath-hold examination (VIBE) and half-Fourier-acquisition single-shot turbo spin-echo (HASTE) fast magnetic resonance imaging (MRI) sequences in the evaluation of pulmonary progressive massive fibrosis (PMF) in comparison with computed tomography (CT) imaging. If fast MRI is proven to be diagnostically significant, this modality can be used for diagnosis and follow-up studies of PMF patients. MATERIALS AND METHODS Twenty-two PMF lesions from 20 coal workers were evaluated. After CT imaging, patients underwent pre-contrast VIBE, contrast-enhanced VIBE, and HASTE MRI studies for detection and evaluation of the PMF lesions. Measurements of the three groups were evaluated with intra-class coefficients. Correlation levels between sizes, image quality, and artifact were evaluated with linear Pearson correlation analysis. RESULTS There was almost perfect agreement among radiologists for lesion detection with kappa analysis. There was significant agreement between three MRI study groups and gold standard CT images. We found the best agreement values with contrast- enhanced VIBE images for lesion detection and image quality in comparison with CT imaging. Presence of artifact was also lowest with this protocol. CONCLUSION With fast MRI sequences in pulmonary imaging, image quality has significantly improved being very close to that of CT studies. In this study, contrast-enhanced VIBE protocol provided the best depiction of PMF lesions. This protocol may be an alternative choice for CT, avoiding the use of iodinated contrast material and minimizing exposure to ionizing radiation for follow-up studies.
Abdominal Imaging | 2010
Koray Hekimoglu; Yucel Ustundag
Cavernous hemangiomas with shunt formations have been a recently recognized entity. Arterioportal (AP) shunts with cavernous hemangiomas have been described. However, a combination of AP and portosystemic (PS) shunts causing portal hypertension has not been previously demonstrated by computed tomography (CT) imaging. In this study, we report an atypical cavernous hemangioma associated with portal hypertension. Cavernous hemangioma with AP and PS shunts formations was precisely demonstrated with dynamic multidetector CT imaging.
Scandinavian Journal of Infectious Diseases | 2008
Nefise Oztoprak; Güven Çelebi; Koray Hekimoglu; Bora Kalaycioglu
Cervical contrast-enhanced computed tomography (CECT) was performed in 16 cases (5M, 11F) of oropharyngeal tularaemia, diagnosed at Zonguldak Karaelmas University, Turkey, between January 2004 and March 2006. All patients showed lymphadenopathy with contrast enhancement, 12 of them with peripheral contrast enhancement. Lymph node necrosis was found in 13 of the patients, abscess formation in 9 and cyst formation in 13. This appears to be the largest series of cervical CECT in oropharyngeal tularaemia reported to date. Tularaemia is a differential diagnosis of massive adenotonsillar enlargement and extensive necrotic cervical lymphadenopathy.
World Journal of Gastroenterology | 2011
Yucel Ustundag; Guray Ceylan; Koray Hekimoglu
There is an ongoing discussion on how to diagnose a hyperechogenic pancreas and what is the clinical significance of diffusely hyperechogenic pancreas. Computerized tomography and magnetic resonance imaging are the more appropriate methods to diagnose pancreatic hyperechogenicity when compared with transcutaneous or endoscopic ultrasound examination. More importantly, pancreatic hyperechogenicity may not be a certain indicator of pancreatic fat infiltration. Even if it is true, we do not know the clinical significances of pancreatic fat accumulation. Some suggested that excess fat in the pancreas is associated with chronic pancreatitis. However, several histological studies on human alcoholic chronic pancreatitis did not prove the presence of fatty pancreas in such cases. Thus, except for aging, it is very rare to have truly steatotic pancreas in the absence of certain human diseases.
Journal of Digestive Diseases | 2010
Koray Hekimoglu; Ahmet Bayrak; Funda Ulu; Mehmet Coskun
Gallbladder duplication is a rare congenital anomaly, and the exact diagnosis of this pathology is important for preventing any clinical and surgical problems. Multidetector computed tomography (MDCT) and magnetic resonance cholangiopancreatography (MRCP) have increasing values in the diagnosis of gallbladder duplication. In this case report we present an evaluation and exact diagnosis of gallbladder duplication using ultrasound, MDCT and MRCP.
Journal of Clinical Ultrasound | 2009
Isik Conkbayir; Bahri Keyik; Koray Hekimoglu; Egemen Cifci; Bahar Yanik
Laryngocele is an uncommon disease defined as an abnormal dilatation or herniation of the laryngeal saccule, forming an air‐filled cavity. Radiologic evaluation of a suspected laryngocele generally includes plain radiographs, CT, and MRI. There are very few reports in the literature on sonographic findings of laryngocele. Trumpet maneuver has been reported in CT examination for the diagnosis of laryngocele. However, to the best of our knowledge, the use of trumpet maneuver in the sonographic diagnosis of laryngocele has not been previously described. This report presents the sonographic findings of an external laryngocele while performing the trumpet maneuver.
Annals of Thoracic and Cardiovascular Surgery | 2011
Dalokay Kilic; Alper Findikcioglu; Yahya Ekici; Utku Alemdaroglu; Koray Hekimoglu; Ahmet Hatipoglu
Annals of Thoracic and Cardiovascular Surgery | 2010
Dalokay Kilic; Alper Findikcioglu; Ufuk Ates; Koray Hekimoglu; Ahmet Hatipoglu